Electronic assemblies have played an increasingly important role in a variety of industries and applications. Alongside with their increasing roles, their complexity has increased as well. Modem assemblies often include numerous and diverse electronic components to assist the assembly in providing a wide range of functions. Although this increase in complexity has provided a plurality of benefits, it can also carry with it manufacturing problems. The increasing number of components, tied with an often decreasing assembly size, often results in highly populated circuit boards. The highly populated circuit boards, in turn, can increase the risk of manufacturing errors and associated scrap costs.
One approach to minimization of manufacturing errors on highly populated circuit boards has been to verify the presence of leads protruding through the circuit boards from the plurality of electronic components mounted thereon. One approach to such testing has been to verify lead presence via an in-circuit test passing current through the board and components after soldering. This approach is highly undesirable for a variety of reasons. It commonly requires testing to be performed on a post-soldered circuit board. This makes error correction, part replacement, or the addition of missing parts complex, time consuming and costly as the soldering procedure has already been performed. Secondly, design and manufacturing requirements may require verification and testing of the electronic components prior to such soldering.
Pre-soldering testing and measuring methods have been utilized to verify lead presence and length. Known methods, however, often remain undesirable or impractical for many applications. Lead presence can be verified by approaches that clinch or trim the leads prior to soldering. These approaches, however, can be impractical for many applications and may prove difficult to implement on circuit boards with high component density. Switching probes can be utilized, but they often do not provide the accuracy and repeatability to verify lead length as desired by many applications.
It would therefore be highly desirable to have a lead tester capable of accurately and repeatably verifying the presence and length of a plurality of component leads mounted on a pre-soldered circuit board. It would further be highly desirable to have such a lead tester that could be utilized efficiently and cost-effectively on circuit boards.